Non potevo non segnalarlo no... 
Download it here.
If you already have a previous build of v2.5 installed then we prefer that you install this update via the built-in update mechanism within Paint.NET. Simply click on the green circle in the main UI toolbar right below the File menu, or go click the menu item Help -> Updates -> Check Now.
Please note that this build will expire on November 8th. An update will be available before then. The final release of v2.5 will not expire.
Source: Paint.NET v2.5 Beta 3 now available